Metadata provides a record of almost anything a user does online, from browsing history – such as map searches and websites visited – to account details, email activity, and even some account passwords. This can be used to build a detailed picture of an individual's life.

Despite pledges by President George W. Bush and American intelligence officials to the contrary, hundreds of US citizens overseas have been eavesdropped on as they called friends and family back home

"Hey, check this out," Faulk says he would be told, "there's good phone sex or there's some pillow talk, pull up this call, it's really funny, go check it out. It would be some colonel making pillow talk and we would say, 'Wow, this was crazy'," Faulk told ABC News.